EFFECTS OF BOUNDARY FRICTION ON TRANSMISSION OF STATIC STRESS THROUGH AND IN CYLINDRICAL TANKS.

Abstract

Experiments to determine the effects of boundary friction on the transmission of static vertical stress through standard 20-30 Ottawa sand in 8-inch I. D. tanks are discussed. In these experiments the tank type, tank height, applied overpressure, sand density, and boundary treatment were varied. Theory and derived values for the coefficient of wall friction are included. Tests showed that the transmission did not vary significantly with overpressure between 1/2 and 6 kg/sq cm (7.11 and 85.32 psi), but decreased as the height of the tank increased. The decrease in transmission with increase in tank height could be approximated by the theoretical equation up to some maximum height. It is concluded that a greased membrane is perhaps the simplest and certainly an adequate means of reducing wall friction to such levels that no correction in the free-field average vertical stress over small areas in the center of the tank should be required. This could be said of a tank with a height even as great as three times its diameter. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1965
Accession Number
AD0614108

Entities

People

  • Phillip A. Abbott

Organizations

  • University of New Mexico

Tags

DTIC Thesaurus Topics

  • Boundaries
  • Coefficients
  • Diameters
  • Equations
  • Free Field
  • Friction
  • Mathematics
  • Membranes
  • Overpressure
  • Standards

Readers

  • Mathematics or Statistics
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).
  • ballistics.